Pump-operating mechanism



3 2 Sheets-Sheet 1 Aug. 18, 925. y

J. E. SHUTT 'PUMP OPERATING MECHANISM Filed March-20. 192

Aug. 18, 1925. 1,550,110

J. E. 'SHUTT PUMP OPERATING MEGHANISM Filed ual-cn 2o. 1923 2sheets-sheet a Patented Aug. 18, 1925.

UNITED STATES JOHN EDWARD SHUTT, 0F STUTTGART, ARKANSAS.

PUMP-OPERATING MECHANISM.

Application filed March 20, 1923. Serial No. 626,370.

To all whom t may concern:

Be it kno-wn that I, JOHN E. SHUTT, a citizen of the United States,residing at Stuttgart, in the county of Arkansas and State of Arkansas,have invented a new and useful Pump-Operating Mechanism, of which thefollowing is a specification.

This invention relates, in general, to mechanism for translating rotarymotion into reciprocating motion, or vice versa; but has more specificreference to mechanism of the said general character which is intendedprincipally for use in the operation of pumps, and particularly those ofthe deepwell, double-piston type.

In the operation of such pumps, it is manifestly desirable that theirrate of delivery shall be as nearly uniform as may be possible; and itis also extremely important that the volumetric rate of discharge, for agiven depth of well and with a liquid of a given specific gravity, shallbe the greatest possible in proportion to the piston displacement and tothe power expended, and that variations in the power utilized shall beas slight and as uniform as possible, instead of there being asuddenly-encountered peak load at some point or points in the stroke ofthe pistons, and particularly at a point or points in the cycle wherethe power of the driving shaft is less effectively applied than at otherpoints, to the production of piston movement. i

When the piston rods of a pump are crank-driven in the usual manner, thepower of the driving shaft is applied least effectively at the beginningand end o-f the stroke, during the peak load, when the speed of thepiston is least, and during reversal of the direction of movement of thepiston; and, as the load decreases after the pickup, due to increase inthe .speed and momentum of the piston and the liquid then being movedthereby, the effectiveness with which power is applied to the movementof the piston increases, and, after reaching its maximum at or near themiddle of the stroke, in turn decreases as the other end of the strokeis approached and the speed of piston movement decreases. Also, thedischarge of the pump is jerky or intermittent, and the average flow issmall in proportion to the piston displacement and the maximum andaverage power utilized.

An important object of my present invention is the provision ofmechanism adapted for the operation of double-piston pumps, and whichwill maintain a higher degree of uniformity of delivery, and morehighlyeflicient output per unit of piston displacement and per unit ofenergy expended, than any mechanism utilized heretofore for a similarpurpose; will render the power employed the most effective upon eachpiston when the load thereon is greatest, and less effective upon eitherpiston during the greater portion of its stroke in one direction thanupon the other piston which is moving in the opposite direction at thesame time, and thereby minimize both the power required at peak load andthe variations in the load imposed upon the power-supply unit; and inwhich the change in the direction of movement of either piston takesplace during move-ment of the other piston in the direction to whichsuch change is made. Other objects are to so design and arrange theparts of the pump-operating mechanism that the means for applying powerto piston movement shall be relatively the most effective when the speedand momentum of the piston and the liquid being moved thereby are least;that, whether the reciprocating members be driven from the rotatingmember, or vice versa, there shall be no dead centre in the completecycle of operation; and that the two pump-rods shall be guidedindependently of each other in their reciprocatory movements.

The operation of my improved pump-operating mechanism, and the manner inwhich the foregoing and other objects are accomplished thereby, willreadily be understood from the following description of the accompanyingdrawings, in which- Fig. l is a side elevation of the pump-operatingmechanism, with the crank-shaft and the fulcrum shafts shown in section;

Fig. 2 is a sectional view, taken substantially on line 2 2 of Fig. l;

Fig. 3 is a sectional view, taken substantially on line 3--3 of Fig. 1;and

Fig. 4 is a sectional view, taken substantially on line 4.-4 of Fig. 1.

1n the preferred form of my invention as illustrated in the drawings, aguide rod l is shown, as constituting means, effective upon thepump-rods, independently of each other, for opposing or restrictinglateral movement of said pump-rods, relative to each other or to thewell-casing (not shown) but it is to be understood that the substitutionof different forms, arrangements, or locations, of the means foraccomplishing said purpose, falls within the scope of my invention.

Slidably mounted upon the guide rod 1, are two similar split collars orsleeves, numbered 2 and 3 respectively, each of which has a projectingflange 4, which terminates in a collar or sleeve 5, provided withoppositely-disposed trunnions 6. Said trunnions arev mounted in splitbearings 7 one of which is located. at one end of each of links 8, apair of such links being provided for each of the collars or sleeves 5,and each link has its other end forked, as shown at 9, so as to embracethe respective legs 10 of the forked end 11 of a bell-crank lever. Twosimilar bell-crank levers are employed, in superposed arrangement, andoppositely-disposed, as indicated at 12 and 13, and each of said leversis pivotally mounted upon a fulcruin shaft 14C, projecting from asuitable support, as 15. Those arms of the two bellcrank levers whichare remote from the arms 11, and which have similarly-shaped slots 16therein, are arranged in superposed position, and a roller 17, cairiedby a crank-shaft 18, which preferably forms part of a driving shaftlocated in a plane passing through the centre lines of the fulcrumshafts 14, and equidistant therefrom, is embraced by both of said slots.Thus, when the crank shaft is rotated said roller will be moved in saidslots to rock the two bell-crank levers, and thereby to impartreciprocating motion to the links 8. The forked ends 9 of links 8, whichare pivotally'connected with the respective parts of the forked ends 11of the bell-crank levers, may be secured thereto in any suitable manner,as by engagement of split bearings 19 on the forked ends 9 with pins 2Oextending through said forked ends 11.

One of the collars or .sleeves 5 is suitably secured upon a tubularpump-rod 21, while the other of said collars or sleeves is secured uponanother pump-rod 22, which is adapted to reciprocate within said rod 21,and which extends between the links of one of the pairs, which areconnected with said rod 21, and is connected with the other pair of saidlinks, as indicated at 23.

From the foregoing description, it readily will be seen that the rockingmovement of the two bell-crank levers, which results from movement ofroller 17 on the crank-shaft 18, within the two slots 16, impartsreciprocating movement, through the links 8, to the pump-rods 21 and 22,the greater part of the movement of one of said pump-rods in eitherdirection being accompanied by similar movement of the other of saidrods in the opposite direction, and the pistons (not shown), intended tobe secured upon said rods, respectively, being correspondingly moved.

During each revolution of the crankshaft 18, the following conditionsare created, successively :-Starting to follow the cycle from theposition of the crank-.shaft shown in Fig. 1, the lever arm 13,connected with pump-rod 22, is at the termination of its downwardmovement, and in position to commence its upward movement, at itsminimum speed, while the lever arm 12, connected with pump-rod 21, isapproaching the termination of its upward movement, with its speedgradually decreasing. Upward movement of rod 22 is now initiated, atgradually-increasing speed and with maximum effectiveness ofpower-application, and upward movement of rod 21 continues until thecrank-shaft is at right angles to the slotted arm of the bell-cranklever 12, whereupon downward movement of rod 21 is initiated, at minimumand gradually-increasing speed, and with maximum and graduallydecreasing leffectiveness of power application. lVhen the crank-shaftreaches the limit of its downward movement, and therefore its centrelies within a plane passing through the centre lines of the two fulcrumshafts 14, the two slots 16 are concentrically superposed; rod 21 isapproaching the iniddle of its downward movement, and is moving downwardat the greatest speed attained by it at any time in itsupward-and-downward travel; and rod 22 has passed the middle of itsupward stroke, and is moving less rapidly, and with greatereffectiveness of power-application, than rod 21, but at increasing speedand with decreasing effectiveness of power-application. As thecrank-shaft now moves toward the pumprods, and upward, rod 21 approachesthe termination of its downward stroke, at decreasing speed andincreasing effectiveness of power-application, while rod 22 approachesthe termination of its upward stroke, at increasing speed and withdecreasing effectiveness of power-application. As the crank- .shaftpasses the position in which it is at right angles to the slotted arm ofbell-crank lever 12, downward movement of rod 21 changes to upwardmovement of said rod, at decreasing speed and increasing eectiveness ofpower-application, and upward movement of rod 22 continues, atdecreasing speed and increasing effectiveness of powerapplication,until, when the crank-shaft is at right angles to the slotted arm of thebell-crank lever 13, upward movement of rod 22 changes to downwardmovement thereof. It is not thought necessary to describe in detail themovement of the respective rods during the remainder of the cycle, sincethe same mechanical principles apply aS during the half-cycle justdescribed.

Thus, it will be noted that reversal of the direction of movement of thetwo rods does not take place simultaneously, but, for a short intervalnear the beginning and termination of the movement of either rod ineither direction, the two rods move in the same direction; the rods donot reach the middle of their respective strokes at the same time; theyat no time move at the same speed, or with the same effectiveness ofpower-application, except for the infinitesimal period between movementof the two rods in the same direction and the change in the direc-tionof movement of the first of them to make such change, the effectivenessof the power-application to the rod initiating its upward movement beingat this instant substantially at its maXimum; the average power requiredfor movement of either rod in either direction is the same as thatrequired for its movement in the opposite direction; and there is nodead centre in the complete cycle of operation. Furthermore, in thepreferred form of the invention, as illustrated in the drawings, theincrease in the effectiveness of the power-application to, and in therate of movement of, the upward-moving piston, immediately following theinitiation of such movement, is greater and more rapid than is the caseat the initiation of downward movement.

Changes in minor details of my improved pump-operating mechanism willdoubtless readily suggest themselves to those skilled in the art towhich it appertains, and I therefore do not desire to limit my inventionto the exact construction shown and described.

Having thus described the invention, what is claimed is Inpump-operating mechanism, the combination with a crank shaft, of a pairof bell crank levers fulcrumed on opposite sides of said shaft, one armof each of said levers having an elongated slot to receive said shaft,the other arm of each of said levers being forked, links connected tosaid forks, a cross head connected to each pair of links, a hollowpiston rod connected to the lower cross head, a piston rod connected tothe upper cross head and extending through said lower cross head andsaid hollow piston rod, a guide rod arranged adjacent said piston rods,and sleeves carried by sail cross heads and surrounding said guide ro Intestimony that I claim the foregoing as my own, I have hereto affixed mysignature.

JOI-IN EDWARD SHUTT.

